Data switching between devices is important for many electronic products which require a plurality of data processors.
Some systems supply data to a plurality of devices but only enable one of them to receive data. Alternatively, data are routed serially through all destinations until a given node recognizes its address in the data header, as described, for example, in U.S. Pat. No. 4,993,025, J. Vesel et al., "High Efficiency Image Data Transfer Network" (Feb. 12, 1991). Such systems suffer from lack of speed because data are handled by a number of nodes in sequence.
Techniques for realizing crossbar switches generally utilize programs stored in random access memory to implement switching decisions and also arbitration in light of plural requests and generally are not able to store a series of data to be switched.
A significant drawback of such approaches has been a limitation on the number of requests which can be simultaneously accommodated, especially requests to supply data to the same node.
What are needed are methods and apparatus for rapidly switching synchronous data interconnections between several data processing/communicating elements.